The manufacturing process of a commercial aircraft comprises the preparing the connection of the fuselage sections. The preparing of the connection and the connection itself is known as complicated and time-consuming, because the connection has to be exact and robust. Particularly with regard to the length of the fuselage, small tolerances of a few millimeters may lead to enormous tolerances of some centimeters at the end portion of the fuselage and causes the fly characteristic of the airplane in an unknown way.
Exemplary a short description should be given about the today's method of preparing the connection of two fuselage sections of an aircraft. The sections with pre-mounted seat bars and stringers are jacked up and moved towards each other and arranged accurately using means, as for instance the seat bars or stringers and/or the width of the slit between the leading edges of the sections (circular slit with a few millimeter constant distance), till the center lines of the barrels, namely the longitudinal axis of the fuselage are in line. Small bars are clamped at the stringers to act as coupling means and to compensate the aforesaid tolerances.
At first the stringers themselves are not fixed between the last circular frame and the front edge of one section. Therefore a further compensation of the tolerances is possible. Furthermore, to compensate the manufacturing tolerances of one section it possesses a lengthwise slit. Circular brackets with calibrated bore holes (CBH) are attached at the inner side of the barrel and overlapped the front edge of one barrel by plugging fixing means as temporary rivets. The radius of the brackets is the same as the associated part of the section.
Beside the other fittings as the aforesaid small bars, the circular brackets may be attached via further fixing elements such as temporary rivets to the other barrel and a drilling template together using tack riveting.
The next process step is to drill pilot holes for every planned final bore hole which is in fact every bore hole through the skin of the sections and the brackets. Because material, such as drilling chips, could penetrate the possible spacing between the relatively thin skin and the circular bracket, it is necessary to disassemble the barrels and the fittings. After drilling the pilot holes into the skin and the circular brackets the boreholes may be deburred and degreased.
In view of the foregoing, it is at least one object of the invention to provide a less complicated and time consuming method of preparing the connection of two fuselage sections (i.e., barrels) of an aircraft. In addition, other objects, desirable features, and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.